Officials say the porcine pollution probably came from farms upstream in the Jiaxing area of neighboring Zhejiang province.
Farmers there are accused of dumping the animals into the Huangpu River because the swine were infected with porcine circovirus, a common pig disease that does not affect humans.
It’s believed the dump was in response to the recent conviction of 46 people who were jailed for producing unsafe pork from sick pigs.
The Shanghai government said water in the Huangpu was within “safe range” and that the carcasses were being collected for burial or incineration.
The waterway provides 22 percent of the city’s water supply.
Photo: Cai Xianmin - Global Times